The present application relates to a liquid crystal display device manufactured by using a One Drop Fill (hereinafter, referred to as “ODF”) method, and more particularly, to a liquid crystal display device suppressing insertion of liquid crystal into a sealing member and generation of air bubbles inside the liquid crystal.
As a method of enclosing liquid crystal in a liquid crystal display device, an ODF method is known. The ODF method is a method in which, before two substrates, for example, an array substrate and a color filter substrate, on which various wirings and the like are formed, are bonded together, any one of the substrates that is disposed on the lower side is coated with a sealing member in a closed loop shape, liquid crystal is dropped into the inside thereof, thereafter, the substrate is covered with the other substrate located on the upper side and bonded therewith, and the sealing member is cured by ultraviolet rays, heat, or the like.
In the ODF method, after coating is performed with the sealing member, the liquid crystal is injected, and thereafter a pair of substrates is bonded together. However, at this time, the sealing member is brought into contact with the liquid crystal in the state in which the sealing member is not cured. Since the liquid crystal is brought into contact with the sealing member for a long time, and pressure is applied thereto at the time of bonding the substrates together, the liquid crystal is inserted into the sealing member that is still in a soft state. Accordingly, there is a problem in that the liquid crystal finally passes through the sealing member so as to cause leakage of the liquid crystal.
On the other hand, a corner portion of the sealing member in the liquid crystal display device is relatively far from the center portion of the liquid crystal display device, compared to the side portion of the sealing member, and accordingly, the liquid crystal material is insufficient therein, and the liquid crystal does not sufficiently spread thereto. Therefore, there is a problem in that air bubbles are generated in a portion in which the amount of the liquid crystal is insufficient.
In order to solve such a problem, a method of manufacturing a liquid crystal display device capable of dropping the liquid crystal with a dropping amount optimized for each substrate is disclosed in Japanese Patent No. 3678974. In other words, according to the method of manufacturing a liquid crystal display device disclosed in Japanese Patent No. 3678974, in the method of manufacturing a liquid crystal display device in which liquid crystal is injected by dropping the liquid crystal onto a substrate, then disposing the liquid crystal dropping face of the substrate so as to face an opposing substrate and bonding the substrates together in vacuum, and returning the pressure to the atmospheric pressure, the optimized amount of the liquid crystal to be enclosed between the two substrates is predicted by measuring the columnar height of a columnar spacer installed so as to determine a cell thickness between the two substrates bonded together, and the amount of liquid crystal to be dropped is controlled based on the predicted value.
According to the method of manufacturing a liquid crystal display device using the ODF method disclosed in Japanese Patent No. 3678974, the amount of liquid crystal optimized for each liquid crystal display panel can be dropped. Accordingly, air bubbles due to an insufficient amount of liquid crystal or an uneven display due to an excessive amount of liquid crystal can be eliminated, whereby it is thought that the liquid crystal display device can be stably manufactured in massive volume.